Computing instrument for making elbows



Nov. 10, 1953 v. w. DALZELL 2,658,672

COMPUTING INSTRUMENT FOR MAKING ELBOWS Filed May 26, 1952 A TTORNEYSPatented Nov. 10, 1953 OFFICE COMPUTING INSTRUMENT FOR MAKING ELBOWSVernon W. Dalzell, Alliance, Ohio Application May 26, 1952, Serial No.289,966

4 Claims. 1

The invention relates to a protractor particularly adapted for use inthe making of elbows for determining the height of rise of the miterline.

An object of the invention is to provide a calculator by means of whichelbows of two or more pieces or sections, for connecting two runs ofpipe at any desired angle, may be easily and quickly made.

Another object is to provide such a device by means of which an elbow ofany desired construction, for use upon pipe of any known diameter, maybe quickly and easily constructed.

A further object is to provide such a device comprising two memberspivotally connected together, the lower member having a straight upperedge and having spiral curved lines scribed thereon, the upper memberhaving its upper edge graduated in inches or other units of measurementand having a perpendicular edge adjacent to the pivot point and locatedat 90 to said graduated edge.

A still further object is to provide such a calculator in which theseveral spiral curves upon the lower member indicate the number ofpieces or sections of which the elbow is to be made.

The above objects together with others which will be apparent from thedrawing and following description, or which may be later referred to,may be attained by constructing the improved calculator in the mannerhereinafter described in detail and illustrated in the accompanyingdrawing, in which:

Fig. 1 is a top view of a calculator embodying the invention, showingthe parts adjusted for the making of an elbow for connecting two runs ofpipe located at a predetermined angle to each other;

Fig. 2 a diagrammatic view showing the manner in which the angle ofoffset of the two runs of pipe to each other is determined;

Fig. 3 a developed view of one section of an elbow showing the manner inwhich the pattern for the section is obtained from calculations madeupon the calculator;

Fig. 4 a side elevation of an elbow which may be constructed by use ofthe calculator; and,

Fig. 5 a diagram showing the manner in which the spiral curve may beplotted by the coordinate system.

Referring first to the calculator illustrated in Fig. 1, the device maybe formed of two members comprising the lower plate, indicated generallyat it), and the upper plate, indicated at I I, both of which may beformed of any suitable material, preferably a transparent plasticmaterial, such as 2 is ordinarily used for the making of draftsmenstriangles and the like.

The lower member H! has the straight upper edge l2 and one perpendicularedge [3 at right angles to the straight edge l2. The upper member I hasthe graduated top edge [4, which may be graduated in inches as shown, ormay have metric system graduations thereon, if desired.

This upper member has the perpendicular edge !5 located at to thegraduated edge l4, and is pivotally connected to the lower member ID atthe upper left hand corner thereof, as by the pivot screw i5 upon whichis located a nut I! for locking the two members in any desired adjustedposition.

The lower member I6 has a calculator formed thereon comprising aplurality of equally spaced radial lines, radiating from the pivot point16 and extending from the vertical line indicated at 0 to the horizontalline indicated at 90, or even greater angles.

The particular embodiment of the calculator illustrated is a 10 inchsize, being especially adapted for use in obtaining the measurements forsections of an elbow for use with a 10 inch diameter pipe.

It should be understood that the calculator may be made in varioussizes, for various other diameters of pipe, although, as will be laterdescribed in detail, the measurements for elbows to fit other diametersof pipe may be quickly and easily computed from this 10 inch sizecalculator.

A spiral, curved line H! is scribed upon the top surface of the lowermember ll}, extending from the pivot point IE to the point where itintersects the horizontal 99 radial line [9 at a point exactly 10 inchesfrom the pivot point.

In Fig. 5 is shown a diagram indicating the manner in which this spiralcurved line l8 may be determined by the coordinate system. It should beunderstood that this diagram is shown on a much smaller scale than thecalculator in Fig. 1, being one-fourth the size thereof.

In plotting this curve by the coordinate system the initial line 26 isdrawn of a length exactly twice the diameter of the pipe for which thecalculator is designed, in the present case the line 20 being 20 incheslong.

At the exact center of the line 2|] the origin or pole 2! is located andwith this center the semicircular arc 22 is drawn connecting at oppositeends with the ends of the initial line 20.

A plurality of radius vectors, as indicated at 23, are drawn from thepole 21 to the are 22, being preferably located at angles of 5 to eachother throughout the entire arc. vertical radius vector 23c, indicatedat the radius vectors to the left thereof are indicated at to 90, andstarting at the right of the radius vector 23a. they are indicatedreversely from 85 to 0.

At the point of intersection of the initial line with the left side ofthe arc 22 is formed a secondary pole 24, from which secondary vectors,as indicated at 25, radiate and intersect the are 22 at the points ofintersection therewith of the radius vectors 23 indicated at 85 to 0 onthe right side of the arc.

The points 26, at which the secondary vectors 25 intersect the radiusvectors 23 of like number, determine the spiral curve is which is thendrawn through the points 2%. This spiral curved line 18 upon thecalculator, as shown in Fig. 1, is used in conjunction with thegraduated edge M of the top member l l to determine the height of riseof the miter line where a two-piece or two-section, elbow is to be made.

Similar spiral curved lines indicated at 2?, 28, 29, 38, 3!, 32 and ('33are scribed upon the top surface of the lower member to for use indetermining the rise of the miter line where 3, l, 5, 6, '7, 8 or 9sections respectively are to be produced for making the elbow.

In using the improved calculator for making an elbow, it is firstnecessary to determine the angle of oiTset between the two runs of pipeto be connected. This may be done as indicated in the diagram of Fig. 2in which the lines and 34 indicate the two runs of pipe to be connected.

The straight edge 52 of the lower member it of the calculator may beplaced against the line 34 and the upper member ll of the protractorswung upon the pivot point it until the per pendicular edge IE3 or" saidupper member is lined up with the line 33. This locates the graduatededge 14 of the upper member l l at a 69 angle as indicated on thecalculator shown in Fig. 1.

Another way to determine this setting of the calculator is to extend theline 33 above the line 34 as indicated in dotted lines at 33a in 2, andthen measure the angle between the line 34 and the extension 33a whichis shown to be 60. The upper member ll of the calculator is then movedto the 60 position as shown in Fig. l.

The workman then decides whether to make the elbow in two or moresections. If he is to make the elbow of two sections he then takes thereading upon the graduated edge M where the same intersects the spiralcurved line l8, which as shown on Fig. l, is 5% inches. This is theheight of rise of the miter line for a twopiece elbow.

Assuming that the workman decides to make the elbow of three sections,he takes a reading upon the graduated edge id or" the upper member atthe point where it intersects the spiral curved line 21 which, as shownon Fig. 1, is about 2%;- inches. This is the height of rise of the miterline for the first section of the three-piece elbow.

To lay out this section of the elbow the workman then draws a circle asindicated at 35 in Fig. 3, the diameter of which is 2%},- inches. Hethen draws a horizontal line, as indicated at 36 in Fig. 3, at anydistance below the circle 35 which may be desired for additional lengthin the section for telescoping with the adjacent end of one run of thepipe.

A vertical line Si is drawn through the center of the circle 35,perpendicular with the hori- Starting with they zontal line 36. Thisvertical line forms the center of the pattern for this section of theelbow. The horizontal line 36 is extended an equal distance to each sideof this center, the length of the horizontal line from the points 33 to35) being equal to the circumference of the section of the elbow.

The circle is then divided into 12 equal parts as indicated by theradial lines 49, and the horizontal line 35 is divided into 12 equalparts, as indicated by the vertical lines 4i. Horizontal lines 42 arethen drawn through the radial division 40 of the circle and intersectthe vertical lines 4|.

A curved line 44 is then drawn through the points of intersection 43 ofthe vertical and horizontal lines 41 and 42 respectively, and this curvewill be the upper edge of this section of the elbow.

As shown in Fig. 4 this section of the elbow is shown in side elevationat 45. The maximum height 48 of the middle section 4? of this elbow willbe twice the maximum height 43 of the section 45, or twice the height ofrise of the miter line plus any additional length desired to give theproper center line radius. The third section 49 of the elbow will be thesame as the section 45, plus any additional length which may be desiredfor telescoping with the pipe.

It will thus be seen that with this improved angle protractor an elbowof any desired number of sections for connecting together two runs ofpipe located at any angle to each other may be quickly and easilyplotted.

The above description has reference to the making of an elbow for a pipeof 10 inches in diameter. If elbows are to be made for pipes of smalleror larger diameter the calculator may be made in such smaller or largersizes as may be required.

However, by using the 10 inch calculator as illustrated, measurementsmay be quickly computed for the making of elbows of larger or small erdiameter. For instance, in the event that an elbow is to be made for a 5inch pipe, the reading upon the graduated edge 14 of the upper member ofthe calculator, where the same intersects any one of the curved lines itor 2'1 to 33, may be divided by 2.

For instance, if a three-section 50 elbow is to be made for a 5 inchdiameter pipe, the reading of 2%,- inches will be divided by 2, theheight of rise of the miter line being 1 inches.

If an 8 inch diameter elbow is to be made, fourfifths or .8 of thereading upon the graduated edge l 4 will be taken as the height of riseof the miter line, etc.

If, on the other hand, a larger diameter pipe is used, the reading uponthe graduated edge of the upper member of the calculator may be addedto. For instance, assuming that an elbow is to be made for a 12 inchdiameter pipe the height of rise of the miter line will be 1 or 1.2times the reading upon the graduated edge l4, etc.

Although the protractor is shown as designed for making an elbow forconnecting two runs of pipe located at an obtuse angle to each other, itwill be possible with the same type of calculator to design an elbow forconnecting two runs of pipe at an acute angle to each other. This may beaccomplished by increasing the height of the lower member in of theprotractor so as to project the curved lines is and 21 to 33 beyond to amaximum of approximately In the foregoing description, certain termshave been used for brevity, clearness and understanding, but nounnecessary limitations are to be implied therefrom beyond therequirements of the prior art, because such words are used fordescriptive purposes herein and are intended to be broadly construed.

Moreover, the embodiments of the improved construction illustrated anddescribed herein are by way of example, and the scope of the presentinvention is not limited to the exact details of construction.

Having now described the invention or discovery, the construction, theoperation, and use of preferred embodiments thereof, and theadvantageous new and useful results obtained thereby; the new and usefulconstruction, and reasonable mechanical equivalents thereof obvious tothose skilled in the art, are set forth in the appended claims.

I claim:

1. A device for determining the height of rise of the miter line formaking elbows, said device comprising a lower member, an upper memberhaving a straight edge graduated with a scale of linear measurementsthereon, means pivoting the end of the upper member to one end of thelower member, there being a spiral curved line on the lower memberextending from the pivot point toward the other end thereof andindicating an elbow having a definite number of sections, whereby in apredetermined relative position of the upper member upon the lowermember the point of intersection of the graduated edge of the uppermember with the spiral curved line on the lower member indicates theheight of rise of the miter line for a particular elbow formed of apredetermined number of sections.

2. A device for determining the height of rise of the miter line formaking elbows, said device comprising a lower member, an upper memberhaving a straight edge graduated with a scale of linear measurementsthereon, means pivoting the end of the upper member to one end of thelower member, there being a spiral curved line on the lower memberextending from the pivot point toward the other end thereof, said spiralcurved line being plotted by the coordinate system and indicating anelbow having a definite number of sections, whereby in a predeterminedrelative position of the upper member upon the lower member the point ofintersection of the graduated edge of the upper member with the spiralcurved line on the lower member indicates the height of rise of themiter line for a particular elbow formed of a predetermined number ofsections.

3. A device for determining the height of rise of the miter line formaking elbows, said device comprising a. lower member, an upper memberhaving a straight edge graduated with a scale of linear measurementsthereon, means pivoting the end of the upper member to one end of thelower member, there being a plurality of spiral curved lines on thelower member extending from the pivot point toward the other end thereofand indicating a plurality of elbows each having a definite number ofsections, whereby in a predetermined relative position of the uppermember upon the lower member the point of intersection of the graduatededge of the upper member with any spiral curved line on the lower memberindicates the height of rise of the miter line for a particular elbowformed of a predetermined number of sections.

4. A device for determining the height of rise of the miter line formaking elbows, said device comprising a lower member, an upper memberhaving a straight edge graduated with a scale of linear measurementsthereon, means pivoting the end of the upper member to one end of thelower member, there being a plurality of spiral curved lines on thelower member extending from the pivot point toward the other endthereof, said spiral curved lines being plotted by the coordinate systemand indicating a plurality of elbows each having a definite number ofsections, whereby in a predetermined relative position of the uppermember upon the lower member the point of intersection of the graduatededge of the upper member with any spiral curved line on the lower memberindicates the height of rise of the miter line for a particular elbowformed of a predetermined number of sections.

VERNON W. DALZELL.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,042,360 Maguire Oct. 22, 1912 2,361,807 Wolfe Oct. 31, 19442,405,113 Clemons Aug. 6, 1946 2,551,997 Cody May 8, 1951 2,562,224Weyrick July 31, 1951

